def _expand_hostlist()

in ignite/distributed/comp_models/native.py [0:0]

• 25 lines of code
• 18 McCabe index (conditional complexity)

    def _expand_hostlist(nodelist: str) -> List[str]:
        """Expand a compressed hostlist string and returns all hosts listed.

        Source : https://github.com/LLNL/py-hostlist/blob/master/hostlist/hostlist.py

        Args:
            nodelist: Compressed hostlist string

        .. note::
            The host names can be composed by any character except the special ones `[`, `]`, `,`. Only one
            sequence `[...]` is supported per hostname.

        .. versionadded:: 0.4.6
        """
        result_hostlist = []

        nodelist_match = r"([^,\[\]]+\[[^\[\]]*\][^,\[\]]*|[^,\[\]]*),?"

        nodelist = nodelist.replace(" ", "")

        for node in re.findall(nodelist_match, nodelist):

            node_match = r"(.+)\[((,?[0-9]+-?,?-?){0,})\](.*)?"

            match = re.search(node_match, node)

            if match is None:
                if node:
                    result_hostlist.append(node)
            else:
                # holds the ranges of nodes as a string
                # now we can manipulate the string and cast it to a list of numbers
                num = str(match.group(2)).replace("[", "").replace("]", "")

                if len(num) == 0:
                    raise ValueError(f"hostlist invalid : {nodelist}")

                num_list = num.split(",")

                # find range of node numbers
                ranges = [elem.split("-") if "-" in elem else [elem, elem] for elem in num_list]

                # if the node numbers contain leading zeros, store them to be
                lead_zeros = max([len(s) - len(s.lstrip("0")) for s, _ in ranges])

                # list of expanded ranges of node numbers
                nodes_list = [list(range(int(s), int(e) + 1)) for s, e in ranges]

                # flat the list
                final_list = [item for sublist in nodes_list for item in sublist]

                # put final list in ascending order and append cluster name to each node number
                final_list = list(sorted(set(final_list)))

                # prepend leading zeros to numbers required
                hostlist_tmp = [str(elem).zfill(lead_zeros + 1) for elem in final_list]

                # append hostname to the node numbers
                hostlist_no_suffix = [match.group(1) + elem for elem in hostlist_tmp]

                # append suffix to hostlist if there is one
                final_hostlist = [elem + match.group(4) for elem in hostlist_no_suffix]

                result_hostlist += final_hostlist

        return result_hostlist